Description:FIELD OF THE INVENTION [0001] The present invention relates to a plasticizer for polyvinylidene fluoride (PVDF), which is used as a binder for electrode fabrication. BACKGROUND OF THE INVENTION [0002] Typically, in a secondary battery for electrochemical energy conversion and storage, two electrodes and an electrolyte are commonly employed with electrochemical reactions proceeding at both electrodes with more or less significant changes in the composition of the electrolyte. Frequently constituents of the electrolyte solution are consumed or new ones are generated during electrochemical process in a cell. The associated changes in properties of the electrolyte are mostly unwelcome because they might, for e.g., result in reduced ionic conductivity and increased internal resistance of the device. For sustained performance of the cell, a certain minimum amount of electrolyte is essential. [0003] Typical examples of metal-ion batteries reported in various studies include sodium-, lithium-, potassium, magnesium, calcium, and fluorine-ion batteries. In general, for any battery, electrode material is a critical factor affecting battery performance and cost relative to other materials. While several studies have been dedicated to materials discovery, notable progress has been made on the engineering front as well. The incentive for improving electrode performance lies largely on the electrochemical storage property of the active material. Nonetheless, the electrode fabrication has a major role which significantly affects the battery performance. In particular, binder, conducting carbon, solvent, and their proportions also have a considerable role in deciding the rate capability, cycling performance, and energy density. [0004] The electrode fabrication procedure is broadly as follows: battery constituents, which include an electrode active material, conductive carbon, and binder, are homogenized in a solvent. The resulting suspension is referred to as electrode slurry, which is then coated on a metal foil, for e.g., Al and/or Cu, to obtain the electrode. There have been several studies focusing on various components of the battery such as electrode, electrolyte, separator and binders. [0005] The main purpose of a binder is to hold the active material together in the electrode and improve the adhesion between the electrode and current collectors. The addition of binder to the active material requires much attention. The quality measurements that have been considered for the choice of appropriate binder are adhesion strength, hydrophilicity, thermal and electrochemical stability to withstand long charge-discharge cycles, and non-toxicity. Additionally, the crystallite size, conductivity and ion-diffusion ability in binders are equally important parameters for consideration. The list of binders includes both natural and synthetic materials. Polyvinylidene fluoride (PVDF) is a semi crystalline polymer widely used in the fabrication of electrochemical devices such as Li-ion batteries, supercapacitors, nanogenerators due to their superior properties such as mechanical, thermal and chemical stability, and non-toxicity. On behalf of the binding efficiency of PVDF, an enormous number of literature have been reported. From this, it was observed that PVDF is a suitable binder for almost all kinds of electrode materials such as activated carbon, carbon nanofiber, graphene, carbon nanotubes, conducting polymers (polyaniline, polythiophene, polypyrrole, and metal oxides). Several documents discussing PVDF as suitable binder have been summarized below: [0006] KR101413433B1 relates to binder material for secondary batteries. The disclosed material includes rosin and rosin derivatives. Additionally, the material may further contain a fluorine containing polymer. The fluorine containing polymer includes PVDF and other copolymers such as PVDF-hexafluoropropylene, and PVDF-tetrafluoroethylene. [0007] WO2016123168A1 discloses a lithium-ion capacitor. The capacitor includes: an anode including: a conductive support; a first mixture coated on the conductive support including: a carbon sourced from coconut shell flour; a conductive carbon black; and a PVDF binder. A second mixture comprising micron-sized lithium metal particles having an encapsulating shell is coated on the first mixture. The encapsulated shell comprises LiPF6, mineral oil, and a thermoplastic binder. [0008] WO2018084431A1 relates to an electrode for a secondary battery capable of preventing a short circuit phenomenon of the electrode. The electrode comprises an active material layer on a current collector, said layer comprising a binder having PVDF. A short circuit prevention layer is formed on the active material layer, the prevention layer comprising a porous polymer fiber web formed of accumulated fibers of a heat-resistant polymer material. [0009] WO2019074025A1 relates to a method for producing an electrode for a non-aqueous electrolyte secondary battery. The method comprises preparing a dispersion by mixing the electrode active material, PVDF binder, a first solvent, and a second solvent. Subsequently, a slurry is prepared by removing the second solvent from the dispersion followed by coating the slurry on current collector. [0010] There are several other state-of-the-art documents discussing PVDF as preferred binder material for electrode fabrication in metal ion batteries. Despite the extensive use and study of PVDF as binder material for batteries, there are several challenges associated thereto. For instance, PVDF is considered not suitable for enhancing the conductivity and ion diffusion, thereby severely impeding the rate performance and cyclability in the long run. Further, carbonate based organic solvents, phthalate compounds, organic acetates and the likes have been used as plasticizers in the state of the art. However, the electrochemical performance is not greatly improved. A suitable plasticizer for PVDF requires controlling the crystallite size of the long chain, thereby improving the conductivity and enabling enhanced diffusion of metal ions (such as Li+, Na+, K+) in and out of the electrode while keeping the particles intact. Since this is not observed in the state-of-the-art, where the plasticizers are directly added during the slurry preparation, without any change in conventional fabrication process, the resulting electrodes are not much valuable from commercial aspect. [0011] In view of the foregoing, plasticizing the PVDF binder is a promising option to ensure one or more of the aforesaid challenges are overcome. Upon plasticizing, the PVDF polymer particles are able to soften, flow and adhere to powdery materials during manufacture, resulting in electrodes with high connectivity that are non-reversible. In view of the same, there is a long-felt need for an electrode slurry, which could provide a facile fabrication technique, which results in enhanced electrochemical properties in the electrode. [0012] It was, therefore, an object of the present invention to provide an electrode slurry effective in mitigating one or more of the challenges in the state of the art. SUMMARY OF INVENTION [0013] Surprisingly, it has been found that the above object is met by providing an electrode slurry described hereinbelow. [0014] Accordingly, in one aspect, the present invention relates to an electrode slurry comprising: (a) 60 wt.% to 98 wt.% of an electrode active material, (b) 0 wt.% to 20 wt.% of conductive carbon, and (c) 1 wt.% to 20 wt.% of a plasticized binder, wherein the wt.% is based on the total weight of the slurry, characterized in that, the plasticized binder comprises: polyvinylidene fluoride, and a plasticizer selected from the group consisting of: tetraglyme, diglyme, triglyme, and monoglyme. [0015] In an embodiment, the plasticizer is present in an amount ranging between 1 wt.% to 50 wt.% based on the weight of polyvinylidene fluoride. [0016] In another embodiment, the plasticized binder is obtained by mixing polyvinylidene fluoride with the plasticizer. [0017] In another aspect, the present invention relates to a method for preparing the above electrode slurry by mixing the electrode active material, conductive carbon, and plasticized binder, in presence of a solvent. [0018] In an embodiment, the solvent is selected from the group consisting of N-Methyl-2-pyrrolidone (NMP), dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), and dimethylacetamide (DMAc). [0019] In still another aspect, the present invention relates to a method for preparing an electrode by coating the above electrode slurry on a current collector. [0020] In an embodiment, the current collector is subjected to drying at a temperature ranging between 50℃ to 200℃. [0021] In yet another aspect, the present invention relates to an electrode obtained from the above method. [0022] In a further aspect, the present invention relates to a battery comprising the above electrode. [0023] In an embodiment, the battery is selected from a lithium-ion battery, a sodium ion battery, a potassium ion battery, zinc ion battery, aluminium ion battery, calcium ion battery, fluorine ion battery, an aqueous battery, and a primary battery. [0024] In another aspect, the present invention relates to an electrolyzer comprising the above electrode. [0025] In still further aspect, the present invention relates to a fuel cell comprising the above electrode. BRIEF DESCRIPTION OF FIGURES [0026] Figures 1(a)-(b) show galvanostatic charge discharge profile, and rate capability of lithium iron phosphate cathode for lithium-ion battery in accordance with an embodiment of the present invention. [0027] Figures 2(a)-(c) show galvanostatic charge discharge profile, rate capability, and cycling capability of graphite anode for lithium-ion battery in accordance with an embodiment of the present invention. [0028] Figures 3(a)-(c) show galvanostatic charge discharge profile, rate capability, and cycling capability of lithium nickel manganese cobalt oxide cathode for lithium-ion battery in accordance with an embodiment of the present invention. [0029] Figures 4(a)-(d) show galvanostatic charge discharge profile, rate capability (with tetraglyme and diglyme as plasticizers), and cycling capability (with tetraglyme as plasticizer) of hard carbon anode for sodium-ion battery in accordance with an embodiment of the present invention. [0030] Figures 5(a)-(c) show galvanostatic charge discharge profile, rate capability, and cycling capability of Na3(VO)2(PO4)2F cathode for sodium-ion battery in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0031] Before the present invention is described, it is to be understood that the terminology used herein is not intended to be limiting since the scope of the presently claimed invention will be limited only by the appended claims. [0032] The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. It will be appreciated that the terms "comprising", "comprises" and "comprised of" as used herein comprise the terms "consisting of", "consists" and "consists of". [0033] Furthermore, the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)", etc. and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. In case the terms "first", "second", "third" or "(A)", "(B)", and "(C)" or "(a)", "(b)", "(c)", "(d)", "I", "ii", etc. relate to steps of a method or use or assay, there is no time or time interval coherence between the steps, that is, the steps may be carried out simultaneously or there may be intervals of seconds, minutes, hours, days, weeks, months, or even years between such steps, unless otherwise indicated in the application as set forth hereinabove or below. [0034] In the following passages, different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous. [0035] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the presently claimed invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Further, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of this invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination. [0036] Furthermore, the ranges defined throughout the specification include the end values as well, i.e., a range of 1 to 10 implies that both 1 and 10 are included in the range. For the avoidance of doubt, the applicant shall be entitled to any equivalents according to applicable law. [0037] As used herein, the terms “charge” and “charging” may refer to a process of providing electrochemical energy to a cell. [0038] As used herein, the terms “discharge” and “discharging” refer to a process for removing electrochemical energy from a cell, for example, when using the cell to perform desired work. [0039] As used herein, the term “positive electrode” may refer to an electrode (often called a cathode) where electrochemical reduction occur during a discharging process. [0040] As used herein, the term “negative electrode” may refer to an electrode (often called an anode) where electrochemical oxidation occurs during a discharging process. [0041] An aspect of the present invention is directed towards an electrode slurry. [0042] In an embodiment, the electrode slurry comprises: (a) 60 wt.% to 98 wt.% of an electrode active material, (b) 0 wt.% to 20 wt.% of conductive carbon, and (c) 1 wt.% to 20 wt.% of a plasticized binder. The wt.% is based on the total weight of the slurry. [0043] The choice of suitable electrode active material depends on the battery and type of electrode, i.e., positive or negative. In an embodiment, the active material capable of intercalating and de-intercalating the metal ion is used, and can be roughly divided into a group of inorganic compounds and a group of organic compounds. [0044] The electrode active material in the group of inorganic compounds may include transition metal oxides, transition metal sulfides, lithium containing complex metal oxides between lithium and the transition metal etc. As the above transition metal, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo and the likes can be used. As for the transition metal oxides, MnO, MnO2, V2O5, V6O13, TiO2, Cu2V2O3, amorphous V2O—P2O5, MoO3, V2O5, V6O13 and the likes may be mentioned. [0045] As the transition metal sulfides, TiS2, TiS3, amorphous MoS2, FeS and the likes may be mentioned. As the lithium containing complex metal oxides, the lithium containing metal oxide having a layered structure, the lithium containing complex metal oxides having spinel structure, and the lithium containing complex metal oxide having olivine structure and the likes may be mentioned. [0046] As for the lithium containing complex metal oxide having the layered structure, lithium containing cobalt oxide (LiCoO2), lithium containing nickel oxide (LiNiO2), lithium complex oxide of Co—Ni—Mn, lithium complex oxide of Ni—Mn—Al, lithium complex oxide of Ni—Co—Al, xLiMaO2.(1-x)Li2MbO3 (wherein, 0